Apparatus for treating the interior of a tubular element



3,207,408. APPARATQS Fo TREA'TING THE INTERIDR 0F .n..TUBuLAR ELEMENT l Filed-April 5, 1962 'fSepL-Zl,l 1965 nfHoM: ETAL 3 Sheets-Sheet. l`

FIG.l

Unitedsefe APPARATUS FOR TREATING THE INTERIOR OF A TUBULAR ELEMENT Paul Thome, Saint-Cloud, Henri Foulquier, Rueil Malmaison, and Jean .-Frehling, Paris, France, assgnors to `Commissariat lEnergie Atomque,Parls,.Frauce t u Filed Apr. 5,` 1962, Ser. No. 185,397 7 Claims. (Cl. 228-29) l Thepresent invention relates to apparatus for treating the interior of a .tubular element and has for an object improvements therein. In particular it is an object of I -the invention to provide apparatus for treating a z one of revolutionwithin a tubular element about the longi- .tudinal axis thereof, particularly for coupling a second tubular-element to the interior of the said irst element by welding.

The apparatus according to the-invention comprises av composite elongated body which is introducible within the tubularelement, and 'carryingmeans for centering the body within the tubular element, a tool mounted on the end part of aimember within'said body, means for the remote control-and radial displacement ofthe tool and for turningthe assembly formed by at least the internal relementof the assembly and the tool about the axis of the tubular element, and wherein 4said body comprises a concrete or because-other elements located around the -pipes prevent access thereto.

This requirement is present, for example, when it is desired to couple a metal tube, -such as a fuel tube passing through the core of a nuclear reactor, to its service pipes: in fact these pipes are embedded in biological protection screens and their coupling zones with the tube are'only accessible through the interior of these pipes;

moreover, if the reactor has already been in operation (in the case of replacing a fuel tube), the radioactivity `in v the coupling zone attains a magnitude which make it dangerous to approach them.

In o rder thatthe invention may be more clearly under-- stood, reference will now be made to the accompanying drawings which show a specific embodiment thereof by `way of example and moreover illustrate some joints capable ofbeing manufactured thereby, and in'which:

FIGURE 1 shows a remotely-controllablev apparatus for 4internal welding and manufactured in conformit with the invention; t

FIGURES 2, 3 and 4 show part axial sections of three embodiments of couplings for tubular elements made by using the said apparatus;

FIGURE 5 is an enlarged detail of a portion of FIG. 1 showing the mechanism for rotating the external tubular FIGURE 6 is an enlarged detail of a portion of FIG. l

showing the means for centering the external tubular member; t

I FIGURE 7 is yan enlarged detail of a portion of FIG. 1

showing the mounting of the torch on the internal tubular member; and l FIGURE 8 is an enlarged detail of a portion of FIG. 1

showing .the means for actuation of the sliding rod,

Referring now to the drawings, FIGURE 1 shows an arent .A the pipe has an internal axial edge and the end of the tube 1 is positioned adjacent this axial edge to form a pair of adjacent annular surfaces 4 which are easily accessible through the interior of the pipe.

The .tubular portionsto bewelded about the pair of annular surfaces 4 are advantageously of a metal or ani alloy such as stainless steel although the central portion of the tube 1 may be constituted of another metal or alloy, for example pure zirconium or an alloy thereof and having a small neutron absorption cross section. composite tube of this type is described in French Patent No. 1,263,814.

The welding apparatus used comprises a hollow elongated support A, centering means locatable in the pipe, a tool B mounted on the said support and movable radially, an optical system C located in the interior of the support and permitting observation of the working zone from the exterior of .the pipe, and a mechanism D for rotating the tool, its control means, and the optical system about the axis of the pipe.

The hollow support A comprises three tubular concentric members, all three generally being composite but they may be in a single piece.

The intermediate tubular member 51 is rotatively connected to the pipe 3 by means of a disk 6 iixed to the tube and carrying dowels 7 which slide axially on lingers S fixed,- for example, by welding or screwing on a plate 9.

This plate 9 may be integralised permanently with the handle 31 (FIG. 8). apparatus for coupling a tube such as 1 by internal weldv pipe 3 but preferably it is secured thereto in such a manner` that it may easily be removed therefrom.

The external tubular member 10 is centered on the member 5. Member 5 has at one of its ends a plate 12 (FIG. 6) provided with cam means comprising a circular groove 132 whose depth is variable in order that the base thereof may present a spiral across section. On the base of groove 133 stops 13 are mounted in radial guiding slots 131 of the member 10 so that it may be rotatably driven thereby. Bearing 11 separates members 5 and 10. The other end Aof the member 10 carries a tangent wheel 14 rotated by a worm screw 15 mounted on the disk 6 (FIG. 5).

vThe internal tubular member 16, centred in the tube 5 by ball or needle bearings 17, carries at its end which is innermost with respect to the pipe 3, a bearing 19 upon which is mounted a centering head 18.

The head 18 is provided with three centering studs 20 which are radially movablein guiding recesses located mutually at about the axis of the head. The projection and the withdrawal of these studs are controlled by a piston 22 coupled to the studs by a controlling mechanism of any desired kind such as a rack and pinion connection 21. The piston 22 is operated by the pressure of a fluid admitted by a conduit 39 and acting on the face of the piston in opposition to the force of a return spring 23 acting on .the other face.

The assembly comprising the tool and its control mechanism B, comprises Ithe tool itself 24 which in this case is a welding torch and which is articulated at 25 (FIG. 7) on bracket 25, fixed to internal tube member 16 opposite a lateral opening 161 provided in the member 16. This tool is oriented by a crank 26 articulated at 27 on the tool 24 and at 28 on a sliding rod 29. The rod is guided by ring 30 located along the internal wall of the member 16, and operable from the exterior by means of a control This handle passes through an opening in member 16 as seen in the drawings.

54 for cold.water for cooling, etc.

Aallows the 'torch to be positioned before welding atv a distance ofk a few tenths of a millimetre.

The yoptical system or endoscope C comprises an axial tube 331 passing into the tubular member 16 and a radial tube 332 projecting out of the window 161and havingI an observation aperture 333. An eye piece 334 carried by the end of the tube'331 disposed outside'the member 16 permits observation of the zone illuminated by a lamp 41.

vAt its end opposite the head` 18, the internal tubular .member carries the mechanism D' which comprises a frame 34 upon which are mounted a motor 35 for driving a pinion 36 meshing with a gear wheel 37 integral with j the disk 6and thusinot rotatable, the motor thus effecting .rotation of themember 16 and the elements which it carries; a drum 42 rotated by a motor which is not shown, the metal wire 43 necessary for welding being coiled on .this drum if use is made thereof; and a drum 44 carrying the'different cables or feedconduits necessary: electrical cable 38 for supplying the welding torch and the motors, a conduit 40 for inert gas for the welding torch,` a conduit These cables and conduits pass through the member'16 through openings which are not shown and provided for this purpose in the wall and the hub of the drum.

The apparatus operates in the following manner:

`Initially, the centering stops 13 and 20 are in the retracted position.

The apparatus is introduced into the pipe 3, head 18 foremost, funtil the member 32 comes into contact with the faces of the axial extensions to be coupled and juxtaposed about the circle 4. At this instant the' lingers 8 are Some examples of joints capable of being made by the apparatus described will now be given.`

FIGURE 2 shows the coupling of two tubular mem-l bers 45 and 46 of different diameters engaged and joined one within the other for a short length:

FIGURE 3 shows the coupling of two other tubular members 47 and 48 of the same diameter and butted end to end on either side of a fillet having a truncated conical shape:

FIGURE 4 shows the coupling of two other tubular members 49 and 50 in.terengaging by means of two com'- A plementary tapered portions; the mechanical strength of the coupling is ensured by a common external sleeve 51 and the welding only carries out lthe function of a seal.'

In FIGURES 2, 3 and 4, 52 indicatesV the ribbonof welding metal and 53 is an arrow representing the direci tion of the'internal welding arc.

The mechanism -for rotating the toolabout the axis ofv the assembly -may be moditied by the addition of a mechanism for axially moving the tool at the same time in such fashion that the tool may operate on not only a part of annular surfaces 'but also a cylindrical surface or a curve v i f any desired shape on such a surface: by such an embodiment it is possi-ble to repair welding lips or to eliminate small amounts of play between tubular elements of different diameters.

Numerical indications relating to two welding operations carried out with apparatus according to the invention and having given every satisfaction will now be given purely by way of illustrative example.

Example 1.-Assembly by welding without welding- A wire, in a single pass, of two tubular elements such as lightly engaged in the dowels 7 for rotatively immobilising the member 5; the head -18 is engaged in .the tube 1 and :the welding .torch 24 is then located in the end enlargel'ment of the pipe 3. f

vCompressed airis then admitted through the conduit 39 behind the piston 22 which is displaced so as to compress the spring 23, separates the centering studs 20 and centres the tubular member 16 in the tube 1. Theworm screw- 15 is also turned in the direction causing the separation of the stops 13 for centering the external tubular member 1,0 in the pipe 3.

By acting upon the handle 31 .the member 32 is withaxis until its working axis cuts-the circle 4 which can be inspected by observation through the endoscope.

` -torch and the` illuminating lamp.

The welding is automatically effected, preferably in accordance with-the known technique of argon arc welding which allows the torch to be inclined to any extent desired. `The quality of the -work .is visually under v surveillance through the endoscope.

.During .the welding the torch may be cooled by cold water admitted through the conduit 54.

lA fter welding it is sufcient to cut off the supplies and l to carry lout movements which are the opposite of those just-described so far as .the radial displacements of the torch, the'centering studs 20 and the stops 13, are concerned, so as to be able todisengage the apparatus from the pipe 3;

' It will be understood that the apparatus which has just been. described may be utilised for effecting welding operations other than that of the tube `1 to the pipe 3 and which is easily disassembled.

' drawn and the torch 24 vis angularly separated from the 45 and 46 (FIGURE 2) in stainless steel 18/8. The internal and external diameters of the internal tube were respectively and 106 mm., and those of the external tube 107' and 113 mm. The welding current strength was 157 A.; the angle of the axis of the torch with respect to l the axis of the tube was 40; the speed of rotation of the torch was 17 cm./min. The diameter of the electrode was 1.6 mm. and its distance from the welding line was about 3 mm.

Example 2.-A welding assembly with welding wire (stainless steel wire of 1.2 mm. diameter fed at a speed of 5.75 metres per minute) of two tubular elements such as 1 and 3 (FIGURE l) in stainless steel 18/8.` The internal and external diameters were respectively 104 and4 114 mm. and those of the lips formed on the external tube were and 125 mm. The welding current strength was 17S A.; the no-load voltagewas 20 volts and the rate of argon -tlow was 22 litres per minute. The resistance of the joint obtained to breaking by tension was 70 tons.

What we claim is:V

v1. In welding apparatus for internally welding a tubular element to a second element having an opening coaxial with the tubular element, a tubular inner member for insertion into the tubular element, means for rotating said inner member about the long axis of the tubular element, a welding tool, means for mounting said welding tool on said inner member -for rotation therewith and for pivotal movement with respect thereto about an axis transverseI to the long axis of the tubular element, an intermediate tubular member spaced from and surrounding said inner member adapted tov be secured against rotation with respect to the tubular element, an outer tubular member surrounding and concentric to said inner and intermediate members, means for rotating said outer tubular member with respect to said intermediate member, centering means supported on said intermediate mem-ber and means for actuating said centering means by relative rotation of said outer and intermediate members about the long axis of the tubular element.

2. Apparatus as claimed in claim 1, wherein means are included for rotating said outer member with respect to said intermediate member.

3. Apparatus as claimed in claim l, wherein means are y provided for displacing said members parallel to the long axis of the tubularelement.

4. Apparatus as claimed in claim 1, including centering members carried by said inner member, said centering means and said centering members being disposed on opposite sides of said tool in the direction of the long axis of said inner member.

5. Apparatus as claimed" in claim 1, including a drum l receiving supply cables for the tool and a motor for rotating said inne'rlmembei and structure secured to said inner member supporting said drum and said motor.

6. Apparatus as claimed in claim 1, wherein the tool consists of gan electric welding torch.

member for pivotal movement of said tool about an axis vtransverse to the axis of rotation of said inner member,

means for adjusting the angularposition of said tool with centering means carried by movement transverse to the axis of rotation o'f said member, an outer tubular member spaced from and surroundl ing said inner member and said intermediate member, cam

means on said intermediate member for actuation of said centering'means upon rotation of. said outer member and vbearing means on said intermediate member rotatably supporting said inner member and said outer member with respect thereto.

References Cited by tile Examiner i UNITED STATES PATENTS WHITMORE A. wILTz, Primafy Examiner.

respect to said-inner member, an intermediate tubular 20 CHARLES W. .LANHAM, MICHAEL V. BRINDISI,

member spaced from and surrounding said inner member,

l Examiners.

said intermediate member for UNITED STATES PATENT OFFICE CERTIFICATE 0F CORRECTION Patent No. 3,207,408 September 2l, 1965 Paul Thome et al.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

In the heading to the printed specification, after line 7 insert the following:

Claims priority, application France, Apr 13, 1961,

PV 858,664 Signed and sealed this 10th day of May 1966.

(SEAL) Attest:

ERNEST W. SWIDER Attesting Officer EDWARD J. BRENNER Commissioner of Patents 

1. IN WELDING APPARATUS FOR INTERNALLY WELDING A TUBULAR ELEMENT TO A SECOND ELEMENT HAVING AN OPENING COAXIAL WITH THE TUBULAR ELEMENT, A TUBULAR INNER MEMBER FOR INSERTION INTO THE TUBULAR ELEMENT, MEANS FOR ROTATING SAID INER MEMBER ABOUT THE LONG AXIS OF THE TUBULAR ELEMENT, A WELDING TOOL, MEANS FOR MOUNTING SAID WELDING TOOL ON SAID INNER MEMBER FOR ROTATION THEREWITH AND FOR PIVOTAL MOVEMENT WITH RESPECT THERETO ABOUT AN AXIS TRANSVERSE TO THE LONG AXIS OF THE TUBULAR ELEMENT, AN INTERMEDIATE TUBULAR MEMBER SPACED FROM AND SURROUNDING SAID INNER MEMBER ADAPTED TO BE SECURED AGAINST ROTATION WITH RESPECT TO THE TUBULAR ELEMENT, AN OUTER TUBULAR MEMBER SURROUNDING AND CONCENTRIC TO SAID INNER AND INTERMEDIATE MEMBERS, MEANS FOR ROTATING SAID OUTER TUBULAR MEMBER WITH RESPECT TO SAID INTERMEDIATE MEMBER, CENTERING MEANS SUPPORTED ON SAID INTERMEDIATE MEMBER AND MEANS FOR ACTUATING SAID CENTERING MEANS BY RELATIVELY ROTATING OF SAID OUTER AND INTERMEDIATE MEMBERS ABOUT THE LONG AXIS OF THE TUBULAR ELEMENT. 